Multiple fuse plug



Feb. 23, 1937. B. I. mess ET AL MULTIPLE FUSE PLUG Filed July 7, 1932 mM M m Patented eb. 23, 1937 I UNITED STATES MULTIPLE FUSE rLUG BenjaminL Moss and Francis J. LandgraffChicago, Ill., assignors to Leopold Moss,Chicago,

Application July 7, 1932, Serial No. 621,198

Claims.

Our invention relates to fuse plugs and particularly to multiple fuseplugs. Fuse plugs of a multiple type contain a plurality of fuseelements with means for successively connecting 3 the fuse elements intothe circuit so that when one is burned out another one will be availableto take its place without inserting a new plug. Suggestions have beenmade for providing visible means for indicating the condition of thedifferlO ent fuse elements in the plug. Plugs having such visible meanssuggested in the past have not been satisfactory for several reasons,but principally because of the fact that the indicating means has notworked out satisfactorily.

The principal object of our invention is the provision of an improvedmultiple fuse plug.

Another object is the provision of a multiple fuse plug having improvedmeans for indicating the condition of the separate fuse elements.

A further'object is to confine discoloration of a translucent member tothe region immediately adjacent the fuse element which is burned out.

Another object is the provision of a greatly simplified multiple fuseelement which can be produced more cheaply and operate moresatisfactorily than other multiple fuse elements heretofore designed.

Other objects and features of the invention will be apparent from aconsideration of the following detailed description taken with the accompanying drawing, wherein Fig. l is an enlarged vertical sectional view;

Fig. 2 is an irregular plan sectional view taken on the line 2-2 of Fig.1;

Fig. 3 is a sectional view taken along the line 3--3 of Fig. 2; I

Fig. 4 is a plan view of the plug:

Fig. 5 is a bottom plan view of one of the members;

Figs 6 to 8, inclusive, are perspective views of some of the parts;

Fig. 9 is a plan view showing the fuse elements before assembly in theplug; and

Fig. ii) is a plan view showing a modified form.

In general, we provide an outer housing or fuse body having a pair ofcontacts, within which is rotatably supported a fuse element carryingplug. The plughas an extension which with the plug proper forms aplurality of closed apertures or chambers through which the fuseelements extend. A translucent member turns with the plug and serves toclose off the apertures in the plug member thus confining the fuseelements so that the heat and gases generated when a fuse element isblown out will be confined to the closed aperture or chamber, and thediscoloration of the translucent element will also be confined to thespace adjacent such chamber.

Referring now to the drawing, the numeral it) indicates a hollow bodymember having the usual 5 shell contact ii and center contact i2. Withinthe hollow body we provide a rotatable plug including a plug body i3 anda plug extension H.

The plug body shown in detail in Fig. 7 is provided with segments i6forming between them 10 fuse element containing channels l1 which extenddown at Ila on the sides of the plug body. The fuse elements l8indicated in Fig. 9 preferably comprise a plurality of strips ofsuitable material crossed to form a spider, it being under- 15 stood, ofcourse, that a suitable stamping having the same shape as the assembledfuse elements of Fig. 9 may be utilized.

The fuse elements are centered and partially supported by a contactextension i9, which ex- 20 tends through apertures 2i in the fuseelements and through an axial port or opening 22 in the housing. Thefuse elements are bent around and. down along the sides of the plug bodyinto the channels in and a retaining washer 23 25 functions to supportthe fuse elements in position. This retaining washer has internalextensions 24 which by extending into the channels lid of theplug bodydefinitely support the lower ends of the fuse elements and cause theretaining 30 washer to rotate with the plug body.

The retaining washer is held in position due to the fact that it extendsoutwardly beyond the main portion of the plug body, its peripherycoinciding with an annular flange l6a on the plug 35 body, and thewasher resting upon a shoulder 26 formed in the interior of the'housing,or body member.

The plug extension is provided with an annular projection 21 whichengages an annular shoulder 28 on the housing. It is also provided witha plurality of squared projections 29 which extend down into thechannels I! on the plug so as to provide a substantially closed chamberimmediately above the narrowed portion l8a of 45 the fuse member whichis the portion that blows or burns out. Apertures 3i running entirelythrough the plug extension put the chamber in communication with atranslucent member 32, preferably a mica disc. An aperture 35 in the 50center of the member 32 accommodates thumbpiece 31. This translucentmember, therefore, serves as one wall of the chamber and substantiallycompletely houses the individual fuse ele-' ments.

The translucent member (Fig. 6) is provided with a plurality of notches33 into which pro-- jections 34 on the top of the plug extension engageserving to turn the translucent member with the plug extension. Sincethe squared extensions 29 engaging in the channels II serve to turn theplug body, it is clear that the translucent member is always in the samerelative position with respect to the plug body, and also with respectto the fuse elements. Should a fuse burn or blow out, the portion of thetranslucent member forming as it were one wall of the chamber in whichthe fuse member is housed, will be discolored but the remaining portionof the translucent member will be maintained in its original condition.

Any suitable means may be employed for holding the housing and plug inassembled relation and permitting a visual inspection of the translucentmember. Preferably we employ a metal cap 36 apertured to pass a thumbpiece 31 for turning the plug and having an aperture 38 for inspectingthe translucent member and fuse beneath the same. The cap issubstantially cup shaped and is clinched around the shoulder 28 on thebody member or housing. This completes the assembly.

For connecting the fuse elements into the circuit, including thecontacts H and I 2, we provide means including extending the contactextensions l9 into the hollow shaft of the contact member l2. Thisserves to connect all of the fuse elements at their center with thecenter fuse contact. For forming the other contact, a

1 spring contact member 39 is provided having a portion extendingthrough the body Ill and wedged between the shell I I and body. Solder Mor other suitable means is, of course, utilized to provide a firmelectrical contact.

As shown in Fig. 2, this spring member is shaped to extend into thechannels Fla and contact with the end of the fuse element contained inthe channel. The plug body 42 between the channels is shaped so thatwhen the plug is rotated 45 in the direction indicated by the arrow, thespring will ride up easily on the portion 42 as on a cam and will dropoff sharply into the next channel Ila. This serves two useful purposes.It produces a clicking sound which audibly indicates to the user of theplug that he has established a second contact. It also has the advantageof making a firm and quick contact which is especially advantageousshould the user by accident leave the current turned on in the plugcircuit.

The functions of our plug and the manner in which it is manufactured andused appear clear from the preceding detailed description. Although anysuitable insulating material may be employed for the parts which are notdesigned 60 to carry current, we obtain good results by using porcelainthroughout. Various molding compounds, serni-soft rubber or condensationproducts may also be used.

The specific form of the plug elements includ- 651mg the plug extensionshown in the drawing are adequate if porcelain is to be used formanufacturing the same.

In the modification shown in Fig. 10, the cap I36 does not extend to thethumb piece 31, as 70 in the main form, but is merely in the. form of aring extending over just sufiiciently to hold the translucent member I32and the plug extension in position. There are certain advantages in aconstruction as shown in Fig. 10 in that all of the 75 openings |3|which comprise the individual chambers can be seen at the same time. Thediscoloration is confined to the region of these chambers and the userof the plug can tell at a glance how many of the fuse elements have beenblown or burnt out.

We have described our invention in detail in order that those skilled inthe art may be instructed in the practice of the same. We limitourselves, however, only by the scope of the appended claims.

What we claim as new and desire to protect by Letters Patent of theUnited States is:

1. In a multiple fuse plug, a housing, a plug having a plurality ofchannels, said plug rotatably supported in the housing, fuse elementssupported in the channels, a plug extension having squared projectionsextending into the channels, and apertures communicating with thechannels whereby to interconnect the plug and plug extension and formindividual chambers for the fuse elements, and a translucent memberclosing said apertures to form in effect one wall of said chambers.

2. A multiple fuse plug as defined in claim 1, including an aperturedcap extending over the separable plug extension and translucent member,attached to said housing and stationary with respect thereto, said plugextension having a projection extending through said cap for rotatingthe same.

3. In a multiple fuse plug, a housing, a pair of contacts on thehousing, a. plug rotatably supported in the housing, said plug havingchannels coinciding to provide a spiderlike depression therein, amultiple fuse element disposed in the spiderlike channel, whereby anumber of individual fuse elements is provided extending radially fromthe center of the plug in said channels, a plug extension having squaredprojections extending into the channels and having aperturescommunicating with said channels whereby to interconnect the plugextension and plug and form a plurality of closed chambers includingportions of said channels, and a translucent member disposed against theplug extension and closing said apertures, and means for successivelybridging the individual fuse elements across said housing contacts whenthe plug is turned.

4. A multiple fuse plug as defined in claim 3, wherein the channels onthe plug-extend along the sides thereof, the individual fuse elementsextending into the said channels, and a retaining washer extendingaround the plug and having projections extending into the channels tohold the fuse elements in position.

5. In a multiple fuse plug, a housing having center and shell contacts,a plug having a plurality of radial channels coinciding to form aspiderlike channel said radial channels extending along the sides of theplug, a multiple spiderlike fuse element disposed in the channels andchannel extensions, an extension from said center contact on the housingto the center of said multiple fuse element, a spring contact membercarried by the housing and in electrical contact with the shell contactadapted to engage the individual fuse elements when the plug is rotated,and means for rotating said plug including a plug extension havingprojections extending into the channels of said plug, and aperturescoinciding with the channels whereby the plug extension and plug aremoved together and individual chambers are formed including saidchanels, and a translucent member rotatable with theplug extension andclosing said apertures.

6. In a multiple fuse plug, a housing closed at one end and open at theother, a screw shell around the lower portion of the housing, a plugcarried in said housing, an axis for said plug comprising a pinextending through the closed end of the housing and entirely through theplug to permit rotation of the plug but carry it permanently in saidhousing, a plurality of grooves on the top of the plug, a spiderlikefuse element carried in the grooves secured at the center by said pinand in electrical contact therewith, a separable plug extension carriedat the closed end of the housing adjacent said plug, having projectionson the underside thereof engaging corresponding grooves to move saidplug upon rotation of said extension, an immovable apertured cap closingthe top of the housing and extending over the sides to retain saidextension in engagement with the plug, a thumb piece integral with theextension extending through an aperture in the cap for turning saidextension, and a spring contact in said housing in connection with saidshell for successively engaging a fuse element to complete an electricalpath through the pin.

7. In a multiple fuse plug, a housing, a fuse carrying body rotatablybut permanently carried in said housing having a plurality of channelson the top surface thereof for carrying the individual fuses, means forrotating said body including a separable cap of insulating materiallying on top of said body and having a plurality of projections on theunderside thereof for engaging in corresponding channels of the body, animmovable cover to close the housing and retain said cap in engagementwith the body, and a thumb piece integral with the cap and extendingupwardly from the center thereof through the cover whereby said cap maybe moved to rotate said fuse carrying body.

8. A fuse plug comprising a casing, a member rotatably mounted insaid'casing and having an axial bore opening to an end face thereof,said end face having a plurality of radial grooves extending to saidbore, fusible elements in said grooves, a closure positioned against thesaid end face and covering the open sides of said grooves, a pin in saidbore connected to the radial inner ends of said elements and having ahead portion restricting the inner end openings of the grooves in amanner cooperating with said closure to substantially isolate thedifferent elements, a connecting terminal on said plug connected to saidpin, a second terminal on said plug, and means operable on rotation ofsaid member to successively connect the outer ends of said elements tosaid second terminal.

9. In a multiple fuse plug, a housing member having an open upper endand provided with center and shell contacts, a member rotatably mountedcentrally of saidhousing member and having a portion thereof projectingfrom said open end of the housing member for manual engagement to rotatethe same with relation to said housing member, a plurality of fuseelements mounted on one of said members within said housing with eachelement having one end electrically connected with one of said contacts.and having their other ends arranged in circumferentially spacedrelation adapted for selective electrical connection with the other ofsaid contacts. a translucent wall extending across said open end of thehousing member and mounted in fixed nonrotativerelationtothememberonwhichsaid fuse elements are mounted and having portions adjacent and infixed relation to each fuse element for individual discoloration whenthe adjacent fuse element is burned out, a spring contact elementelectrically connected to the other of said contacts and mounted infixed relation to the other of said members in a position to contactsaid other ends of the several fuse elements successively in relativerotation of said members, and closure means extending from andcooperating with said manually rotatable member to complete the closureof said upper end of the housing member, said closure means having asingle sight opening formed therein and being fixed nonrotatably withrespect to the member upon which said spring contact is mounted withsaid sight opening in alinement with said spring contact so as to exposeto view and direct the user's attention to the fuse element in circuitwith said spring contact.

10. A multiple fuse plug comprising, in combination, an insulatinghousing member having an open end and having center and shell contactsat the other end, an adjusting member mounted ,rotatably in said openend of said housing member and having a portion extending from said openend for manual engagement to effect relative rotation of said members, aplurality of fuse elements mounted within said housing member and infixed relation to one of said members with one end of each element inelectrical circuit with one of said contacts and with their other endsarranged in circumferentially spaced relation adapted for selectiveelectrical connection with the other of said contacts, a spring contactelement electrically connected to said other of said contacts andmounted in fixed relation to the other one of said members in a positionto contact said other ends of said fuse elements successively inrelative rotation of said members, a translucent wall extending acrosssaid open end of the housing member in fixed non-rotative relation tosaid fuse elements, said fuse elements having reduced portions locatedadjacent to the inner side of said translucent wall and incircumferentially spaced relation to each other, means within saidhousing member and adjacent and in fixed non-rotatlve relation to theinner side of said translucent wall defining a plurality of chambersopening toward and against said inner side of the translucent wall, onesuch chamber being formed between the reduced portion of each fuseelement and said wall and acting to confine the flame and the resultingdiscoloration to a particular section of said translucent wall, andclosure means extending from said rotatable adjusting member along theouter face of said translucent wall and cooperating with said rotatablemember to complete the closure of said outer end of the housing member,said closure means being fixed non-rotatably with respect to the memberwith which said spring contact is associated and having a single sightopening therein positioned for alinement with the particular fuseelement in circuit with said spring contact so as to expose and directthe users attention to the fuse element in operative relation at anyparticular setting of the parts, and by the condition of the exposedportion of the translucent wall to indicate the condition of theparticular fuse element in circuit.

BENJAMIN L. M088. FRANCIS J. LANDGRAI'.

